Heating unit having transparent window

ABSTRACT

A HEATING UNIT HAVING GLASS WALLS OR DOORS WHERE A COOL VERTICAL CURTAIN OF AIR IS PROVIDED OVER THE GLASS BY PROVIDING A TOP AIR VENT SO THAT MOST OF THE AIR ENTERS MAINLY AT THE TOP OF THE FIREPLACE WITH A SUBSTANTIALLY VERTICALY VELOCITY VECTOR DOWNWARD ACROSS THE GLASS.

Nov. 2, 1971 H. w. HANNEBAUM 3,616,788"

HEATING UNIT HAVING TRANSPARENT WINDOW Filed Dec. 22, 1969 2sheets-sheet 1 INVENTOR. HAROLD W. HANNEBAUM ATTORNEYS Nov. 2, 1971 H.w. HANNEBAUM 3,616,783

- HEATING mm HAVING TRANSPARENT wmnow Filed Dec. 22, 1969 2'Sheets-Sheet a w an 59 I x so 1 52 5 INQENTOR, HAROLD W. HANNEBAUM vATTORNEYS FIG. 5

3,616,788 Patented Nov. 2., 1971 3,616,788 HEATING UNIT HAVINGTRANSPARENT WINDOW Harold W. Hannebaum, Gooding, Idaho (P.O. Box 264,Bellevue, Idaho 83313) Filed Dec. 22, 1969, Ser. No. 887,103 Int. Cl.F24b 1/18 U.S. Cl. 126-135 Claims ABSTRACT OF THE DISCLOSURE A heatingunit having glass walls or doors where a cool vertical curtain of air isprovided over the glass by providing a top air vent so that most of theair enters mainly at the top of the fireplace with a substantiallyvertical velocity vector downward across the glass.

BACKGROUND OF THE INVENTION The present invention is directed to aheating unit and more specifically to a unit having a transparent windowwhich is a portion of the over-all fire box of the heating unit.

When it is desired to provide a heating unit in the form of either, forexample, a free standing fireplace or an installed masonry fireplace, ofthe type which includes a portion of its fire box wall as glass the heatof the fireplace tends to disintegrate the glass. In addition, even inthe absence of excessive heat, the glass accumulates soot, etc., fromthe smoke of the fire. In an issued patent to the same inventor as thepresent application entitled Heating Unit, Ser. No. 711,552, Pat. No.3,499,432 issued Mar. 10, 1970, a type of fireplace is shown with glasswalls in which the whirling action of the air within the fire box keepsthe glass clean and insulates the glass from the heat of the fire. Adesign of this type does not readily lend itself to existing masonryfireplace installations.

On other glass doored fireplaces that are now being marketed air usuallyenters in a straight line at both the top of and bottom of the fireplaceand thus there is no curtain of cool air to protect the glass from bothsmoke and heat. However, in these types of fireplaces the air merelyenters around the glass door and is pulled directly upward from the top;the bottom entering air is attracted by the effective vacuum formed bythe fire at the bottom of the fire box.

OBJECTS AND SUMMARY OF INVENTION It is therefore a general object of thepresent invention to provide an improved heating unit which includes atransparent window.

It is another object of the present invention to provide a heating unitof the above type in which the transparent window is protected from bothsmoke and heat.

Another object of the invention is to provide a heating unit as above inwhich a curtain of cool air is provided against the interior of thetransparent window.

It is another object of the invention toprovide a heating unit as abovewhich is useful for both free standing and installed masonry fireplaces.

In accordance with the above objects there is provided a heating unitcomprising fire box means including substantially air impervious lighttransmitting window means as a portion of one of its walls. Vent meansin proximity to the top of fire box admits air thereto having aconfiguration so the velocity vector of entering air is substantiallydownwards along said window means, this vent means is substantially theonly means for air to enter the firebox.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view takenfrom the side elevation of a masonry fireplace embodying the presentinvention;

FIG. 2 is a front view of the fireplace of FIG. 1;

FIG. 3 is a detail view of a portion of FIGS. 1 and 2;

FIG. 4 is a perspective view of an alternative embodiment of a fireplacewhich is of masonry type construction; and

FIG. 5 is a cross-sectional view of a free standing fireplaceillustrating yet another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring generally toFIGS. 1, 2 and 3 the heating unit of the present invention includes firebox means 10 which has a rectangular glass door which is substantiallyair impervious but of course transmits both heat and light from the fireindicated at 12. The door is hinged at the bottom at pivot axis 13 andis slightly ajar from the front wall 16 of the fireplace leaving forexample a /2 inch to inch opening at the top of the door. In addi tiondoor 11 overlaps the top edge 16 of the rectangular fireplace openingapproximately inch to of an inch. This overlap is best shown in FIG. 2which illustrates that the overlap occurs on both the top edge 16 of thefireplace and the sides 17 and 18. The pivot axis 13 of the door 11 is apredetermined distance 21 from the fireplace floor 19 and in thepreferred embodiment this distance is approximately four inches Thus theglass door 11 in conjunction with the front wall 15 of the fireplaceforms vent means in proximity to the top edge 16 of the fire box whichbecause of the overlap admits air having a velocity vector which issubstantially vertical downward along the window vanes. This vector isshown at 22. More particularly the vent means includes the horizontalslit formed by the upper portion of door 11 with the top edge 16together with the side openings of the door as indicated at 23 whichprovide wedge shaped openings to allow some air to enter the sides ofthe fire box.

From a theoretical standpoint it is believed that air entering at thetop of the glass door has more velocity than that entering at the sides.This therefore tends to bend the side air downwards and outwards fromthe glass, thus breaking up any rolling air and keeping the verticaledges of the glass clean. Because of the overlap at the edges of thefireplace opening and especially the top overlap and the greatereffective area of opening at the top of the glass door, most of the airenters at the top with a smaller amount at the sides. This top enteringair has a velocity vector substantially vertically downward along theinterior of the glass door 11 to provide a cool curtain of air.

In accordance with the above theory the bottom of the door below itspivot axis 13 must be securely sealed against air leaks since it isbelieved that any tiny air whirl at the bottom corners would bedeleterious to the vertical air curtain of the fireplace. The oifset 21of the axis 13 from the bottom 19 of the fireplace eliminates thiseffect.

It is also preferred that the flue opening be at the back of thefireplace since this tends to draw the smoke and gases away from theglass door. An eight inch flue is believed to provide a faster lift anda better balance with the very small amount of air that will enter thefireplace through the vents provided.

In order to properly initiate a good draft, door 11 must be opened tento twelve inches until the fire has properly heated the fire box chamber10.

The details of the pivot 13 along with a means for adjusting the openingof the glass door with respect to the fireplace wall is illustrated in'FIG. 3. The pivot is of the lift off type and includes a horizontal rod24 which is spaced from bottom 19 of the fireplace by a vertical supportmeans 26. The support means 26 also provides an air tight seal from thebase of the fireplace to the pivot point. The rotary part of the pivotincludes an arcuate portion 25 fastened to the base of door 11 which isadapted for rotation on the rod 24.

The means for adjusting the top opening slit and the tapered side slitsformed by the door is indicated generally at 27. They include a stud 28extending from the top end of door 11 which meshes with one of the teeth29 of catch 30 which is pivoted at 31 on the front fireplace wall 15.The various teeth 29 may be used to adjust the spacing of door 11 fromthe rectangular fireplace aperture to provide the proper draft. Finallya chain 33 couples the door to the wall 15 to allow for a wider openingfor placing wood in the fire box, etc.

FIG. 4 shows an alternative embodiment of the invention which has doubleglass doors 40 and 41 which are hinged to vertical portions ofrectangular frame 42. The frame includes a top slit portion 43 and wedgeshaped or tapered side air intakes 44 and 46. As was true with thefireplace unit of FIGS. 1 and 2 the air intakes overlap the rectangularfireplaceaperture 47 to provide the proper vertical air vector.

Other types of glass doors may of course be used including sliding andFrench type. Also it is apparent that upper and side draft air intakesmay be adjustable.

The embodiment of FIG. shows either a cylindrical or a square freestanding fire box 50 having a refractory fire bowl 51 with glass panelsand side windows 52. A top sealing plate 53 seals the fire box 50 andprovides support for the funnel 54 which tapers into the chimney unit56. Funnel 54 includes a spreader unit 57 Top plate 53 includesapertures58 which may be in theform of circular holes to allow air to enter witha vector shown at 59 to provide a vertical curtain of air against thewindows 52 which extends down past the windows into the fire bowl 51 andthen up into the funnel 54.

It is believed that in the embodiment of FIG. 5 the top location of theplate 53 with its apertures 58 provides a proper vertical air vectorwithout need of any overlap.

Thus the present invention provides an improved fireplace especiallyuseful with glass type windows or doors where the input air ventsprovide a cool curtain of air across the glass windows to keep themsmokeless and cool. This provides a fireplace which is estheticallypleasing, has good combustion qualities and provides a reasonable amountof heating.

What is claimed is:

1. A heat unit comprising fire box means including substantially airimpervious light transmitting window means as a portion of its wall,vent means in proximity to the top of said fire box to admit air theretosaid vent means having a configuration so the velocity vector ofentering air is substantially downward along said window means, saidvent means being substantially the only means for air to enter said firebox said vent means including a horizontal slit near the top of saidfire box means where most of said air enters.

2. A heating unit as in claim 1 where said vent means is formed by anoverlap of said window means with another portion of said fire box.

3. A heating unit as in claim 2 where said said horizontal slit isformed by the top of said window means and said vent means also includeswedge-shaped openings formed by the side of said window means.

4. A heating unit as in claim 1 where said window means is the entrancedoor to said fire box together with means for spacing the upper portionof said door away from the wall of said fire box to provide said slitfor admitting air with said velocity vector.

5. A heating unit as in claim 1 where said fire box includes arectangular aperture said window means closing said aperture and beingpivoted at the bottom of said aperture to provide said slit at the topof said aperture to allow the entrance of air with said velocity vector.

6. A heating unit as in claim 5 together with means coupled to saidwindow means for adjusting the width of said slit.

7. A heating unit as in claim 5 where said Window means is of the sameconfiguration as said rectangular aperture but slightly larger toprovide an overlap around said aperture.

8. A heating unit as in claim 5 together with pivot means for saidwindow means including a horizontal rod fastened to the base of saidfire box and an arcuate portion extending from said window means whichis adapted for rotation on said rod.

9. A heating unit as in claim 1 where said fire box includes arectangular aperture with a frame having slits proximate to the top andupper parts of the sides to admit air to said fire box said window meansincluding a pair of doors pivoted on the sides of said frame to allowsaid door to swing in a substantially horizontal are.

10. A heating unit comprising fire box means including substantially airimpervious light transmitting window means as a portion of its wall,vent means in proximity to the top of said fire box to admit air theretosaid vent means having a configuration so the velocity vector ofentering air is substantially downward along said window means, saidvent means being substantially the only means for air to enter said firebox, said fire box including a top sealing plate for receiving a chimneyand holes around its periphery in proximity to said window means forallowing air to enter with said velocity vector.

References Cited UNITED STATES PATENTS 1,430,013 9/1922 Hopkins et a1126--135 3,162,188 12/1964 Tompers 126140 FOREIGN PATENTS 578,796 7/1946 Great Britain 126-140 667,570 3/1952 Great Britain 126-202 CHARLESI. MYHRE, Primary Examiner US. Cl. X.R. 126--140, 202

